Electric motor.



W. THQMASON.

ELECTRIC MOTOR.

APPLICATION FILED OCT. 21. I9l4.

1,208,404. Patented Dec. 12, 1916.

2 SHEETSSHEET 2. 229 5 n4: mu min q. mum. Inland. I r:

, UNITED STATES PATENT OFFICE.

WILLIAM THOMASON, OF SAPULPA, OKLAHOMA, AS SIGNOB OF ONE- HALF T JOHN C. BEDIGREW, OF SAPUIJIJPA, OKLAHOMA.

ELECTRIC MOTOR.

Specification of Letters Patent.

Patented Dec. 12, 1916.

Application filed October 21, 1914. Serial No. 867,840.

To all "whom it may concern Be it known that I, \VILLIAi-I THOMASON, a citizen of the United States, residing at Sapulpa, in the county of Greek and State of Oklahoma, have invented certain new and useful Improvements in Electric Motors, of which the following is a specification, reference being had to the accom panying drawings.

This invention comprehends certain new and useful improvements in electric motors, and the invention has for its primary object a simple, durable and efficient device of this character which will be inexpensive to manufacture and not liable to get out of order.

F ora full understanding of the invention, reference is to be had to the following description and accompanying drawings, in which Figure 1 is a front elevation of the device with the top plate of the casting or mounting of the device removed, Fig. 2 is a hori- -zontal sectional view therethrough, and Fig.

3 is a perspective view of a commutator removed with the segments thereof separated.

Fig. 1 is a diagrammatic view disclosing the circuits used in the device. Fig. 5 is a fragmentary sectional view of parts in side elevation.

In describing the invention, I shall refer to the drawings in which similar reference characters designate corresponding parts throughout the several views and in which 1 indicates a frame or housing such as is usuallyprovided for devices of this character, in the corners of which are mounted the blocks 2 forming the body portions of the stator. This frame or housing 1 is preferably rectangular in cross section and the diagonals thereof may be said to be the lines of centers of the pole pieces or shoes, said lines of centers also passing centrally through the blocks or body portions 2 of the stator.

Pole limbs 3 having threaded stems formed thereon are removably engaged with threaded sockets formed in the body portions 2, said pole limbs forming the cores of the stator magnets and each of these pole limbs or cores is arranged on the respective body portion 2 so as to be offset from the line of center passing through the latter. These cores are each offset from the adjacent lines of centers the same degree, and formed on the outer ends of said cores are pole pieces 5.

These pole pieces are arran ed so that the lines of centers pass direct y through the centers of the same and the free ends thereof are spaced equally from one another. Vires are wound about the cores 3 in the usual manner so as to form the stator magnets, said wires being connected at their one ends to the source of energy and at their other ends to the brushes 6 which are arranged in the usual manner in the space between the pole pieces.

Rotatably mounted in the walls of the casing or housing 1 at the point of intersection of the lines of centers thereof is a shaft 7 which forms the axis of the rotor. A body portion 8 is carried on the shaft and engaged with threaded sockets 9 in the faces of said body portion are the threaded stems of the additional poles 10, these additional pole limbs 10 being of similar design to the pole limbs 3 heretofore described, and said pole limbs 10 form the cores of the rotor magnets. These pole limbs or cores 10 are each offset from the lines of centers in the opposite direction from the direction in which the poles or cores 3 are offset, as clearly disclosed in Fig. 1 of the drawings, and the outer ends of the cores or poles 10 have the pole pieces 11 formed thereon concentric to the outline of the aforesaid pole pieces 5 with which they cooperate. These pole pieces 11 are of lesser diameter and thereby form the air-gap which exists between them and the pole pieces 5. These pole pieces 11 are arranged so that the lines of centers or diagonals of the frame pass centrally therethrough, and in a like manner through the pole pieces 5.

Mounted on the shaft 7, adjacent the rotor is the commutator 12 which, as usual, is designed for cooperation with the brushes 6. This commutator consists of a pair of segments 18 and 14, which are designed similar to one another whereby projecting portions of one may be received in the cut-away or offset portions of the other. As indicated at 15, insulation is disposed between the edges of the segments at points where they are brought together, and a tubular insulation 16 is arranged in the commutator 12 to fit over the shaft 7. Set screws 17 extend into the segments of the commutator to secure the latter in place and the tubular insulation 16, and said segments are provided with flanges 18 with which are engaged the lead wires extending from the rotor magnets which are disposed on the cores 10. The coils of the rotor magnets are wound in series and connected in multiple at the commutator in the usual and preferred manner.

It must here be understood, as can be seen from Fig. 1 of the drawings, that the rotor magnets, the stator magnets, the brushes, and the space of insulation between the segment sections of the commutator all have a definite relation one to the other, in that the spacing therebetween is exactly the same.

When current is passed into the device, the strong ends of the magnets of the stator and rotor, that is, the portions at the junction of the pole pieces with the cores, tend to become directly opposite one another and in tending so to do, they cause the commutator to move across the brushes when the machine is started in the direction of the arrow A, as indicated in Fig. 1 of the drawings. This is obviously due to the offsetting of the cores, and it will be seen from this construction that at no time can these devices be said to be in a position of dead center. W hen the brushes are moved around the eonnnutator the length of one segment thereof the machine will start in reverse direction, that is, in the direction of the arrow B, as indicated in Fig. 1. In doing so, however, the rotor will start to move in the direction of the arrow A for a short distance whereupon it will quickly stop this motion and start to revolve in the direction of the arrow B.

From the foregoing, it will be seen that I have provided a simple, inexpensive, and eliicient means for carrying out the objects of the invention and while I have particularly described the elements best adapted to perform the functions set forth, it is obvious that various changes in the form, proportion and in the minor details of construction may be resorted to,,within the scope of the appended claims, without departing from the spirit or sacrificing any of the principles of the invention.

Having thus described my invention, what I claim, is:

1. A motor of the class described comprising a casing, a stator and a rotor disposed therein, each being provided with pole limbs Uopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

lines passing through the corners of the casing lying in a plane normal to the axis of the rotor, the limbs of the rotor being oppositely displaced with respect to the stator limbs, and poles pieces for the several limbs of segmental shape, the disposition thereof on the limbs being such that the diagonal lines of the casing pass through the centers of the segmental pieces.

3. In an electric motor of the class described, a casing of rectangular design having solid body members of triangular design mounted in the corners thereof, the inner faces of said body members being provided with threaded sockets whose axes are arranged in planes offset to one side respectively of the planes of the diagonals of the casing lying in a plane normal to the axis of the rotor, core members having threaded stems engaged with the threaded sockets of said body members, pole pieces formed integral with the outer ends of said core members, and means for energizing said core members and pole pieces.

4. In a motor of the class described, a casing, a stator and rotor suitably arranged therein, each being provided with the usual magnets, the magnets of said stator and rotor being respectively circumferentially offset in opposite directions from the diagonal lines passing through the corners of the casing lying in a plane normal to the axis of the rotor.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

WILLIAM THOMASON. l/Vitnesses R. E. RUssELL, V. R. ()ANNON. 

